Health Information

All About Asthma

What is asthma?

Asthma is a chronic, inflammatory disease in which the airways become sensitive to allergens (any substance that triggers an allergic reaction). Several things happen to the airways when a child is exposed to certain triggers:

The lining of the airways become swollen and inflamed.

The muscles that surround the airways tighten.

The production of mucus in increased, leading to mucus plugs.

All of these factors will cause the airways to narrow, thus making it difficult for air to go in and out of your child's lungs, causing the symptoms of asthma.

Facts about asthma:

According to the latest information available from the American Lung Association, the Centers for Disease Control and Prevention (CDC), and the National Institute of Allergy and Infectious Diseases (NIAID):

Approximately 20.3 million people in the US have been diagnosed with asthma, with at least 6 million of them children under the age of 18.

Asthma is the leading, serious, chronic illness among children in the US.

Asthma accounts for 14 million absences from school each year.

Asthma is the third-ranking cause of childhood hospitalizations under the age of 15.

What causes asthma?

The exact cause of asthma is not completely known. It is believed to be partially inherited, but it also involves many other environmental, infectious, and chemical factors.

After a child is exposed to a certain trigger, the body releases histamine and other agents that can cause inflammation in your child's airways. The body also releases other factors that can cause the muscles of the airways to tighten, or become smaller. There is also an increase in mucus production that may clog the airways.

Some children have exercise-induced asthma, which is caused by varying degrees of exercise. Symptoms can occur during, or shortly after, exercise. Each child has different triggers that cause the asthma to worsen. You should discuss this with your child's physician.

The changes that occur in asthma are believed to happen in two phases:

An immediate response to the trigger leads to swelling and narrowing of the airways. This makes it initially difficult for your child to breathe.

A later response, which can happen four to eight hours after the initial exposure to the allergen, leads to further inflammation of the airways and obstruction of airflow.

What are the symptoms of asthma?

The following are the most common symptoms of asthma. However, each child may experience symptoms differently. Symptoms may include:

coughing (either constant or intermittently)

wheezing (this is a whistling sound that may be heard while your child is breathing)

trouble breathing or shortness of breath while your child is playing or exercising

The symptoms of asthma may resemble other problems or medical conditions. Always consult your child's physician for a diagnosis.

Who is at risk for developing asthma?

Although anyone may have asthma, it most commonly occurs in:

children by the age of 5.

a child with a family history of asthma.

children who have allergies.

children who have exposure to secondhand tobacco smoke.

What happens during an asthma attack or asthma exacerbation?

Children with asthma have acute episodes when the air passages in their lungs become narrower, and breathing becomes more difficult. These problems are caused by an over-sensitivity of the lungs and airways.

The lungs and airways overreact to certain triggers causing:

the lining of the airways to become inflamed and swollen.

tightening of the muscles that surround the airways.

an increased production of mucus.

Breathing becomes harder and may hurt.

There may be coughing.

There may be a wheezing or whistling sound, which is typical of asthma. Wheezing occurs because of the rush of air which moves through the narrowed airways.

How is asthma diagnosed?

To diagnose asthma and distinguish it from other lung disorders, physicians rely on a combination of medical history, physical examination, and laboratory tests, which may include:

spirometry-a spirometer is a device used by your child's physician that assesses lung function. Spirometry, the evaluation of lung function with a spirometer, is one of the simplest, most common pulmonary function tests and may be necessary for any/all of the following reasons:

to determine how well the lungs receive, hold, and utilize air

to monitor a lung disease

to monitor the effectiveness of treatment

to determine the severity of a lung disease

to determine whether the lung disease is restrictive (decreased airflow) or obstructive (disruption of airflow)

peak flow monitoring (PFM)-a device used to measure the amount of air a person can blow out of the lungs. During an asthma or other respiratory flare up, the large airways in the lungs slowly begin to narrow. This will slow the speed of air leaving the lungs and can be measured by a PFM. This measurement is very important in evaluating how well or how poorly the disease is being controlled.